Background: Ischemic stroke often results in long-term motor impairments due to disrupted corticospinal pathways. Transcranial magnetic stimulation (TMS) motor mapping is a non-invasive technique used to assess corticospinal integrity by measuring motor evoked potentials (MEPs). This study investigates whether MEP amplitudes can predict impairment severity and functional performance in chronic stroke. Methods: Four non-human primates (NHPs) with chronic stroke (> six months) following transient right middle cerebral artery occlusion underwent TMS motor mapping using neuronavigation under ketamine anesthesia. Single pulses of TMS (50-70% of maximum stimulator output) were applied to the affected and contralesional primary motor cortices to elicit MEPs and assess cortical excitability. Intramuscular electromyography recorded muscle responses from the biceps, extensor digitorum longus, and abductor pollicis brevis. Neurological dysfunction was evaluated daily for three weeks using the NHP Stroke Scale, NHP Upper Extremity Motor Dysfunction Scale, and the primate Rankin Scale. Results: MEPs were present in NHP1, NHP3, and NHP4 but absent in NHP2. Stronger MEPs correlated with lower impairment severity and better functional performance, while NHP2 exhibited higher impairment and poorer performance. Conclusions: MEP presence and strength can serve as biomarkers of motor recovery potential, highlighting their role in assessing corticospinal integrity and functional outcomes.